332 PRACTICAL BOTANY. 



ORDER CXIV. 



LEMNACE^, OR DUCKMEATS. 



Genus : 



1. Lemna, L. Duckweed. Duck's- meat. Species 5. 



ORDER CXV. 



najadace.e, or najads. 

 Genera: 



\. Najas^Jj. Najad. Species: JVaJas JlextUs^ Uostk. 



2. Zanichellia, Micheli. Horned Pondweed. Species : 



Zanichellia palustris, L. 



3. Zostera, L. Grass-wrack. Eel-grass. Species: 



Zostera marina., L. 



4. Ruppia^ L. Ditch-grass. Species : 



Ruppia maritima, L. 



5. Potamogeton, Tourn. Pondweed. Species 12. 



ORDER CXVI. 



1. Triglochi7i, L. Arrow-grass. Species 2. 



2. Scheuchzeria^ L. Species: Scheuchzeria palustris, L. 



3. Alis7na, L. Water-Plantain. Species: 



Alisma Plantago, L. Vor. Americaiium. 



4. EchinodoruSy Rich. Species 3. 



5. Sagittaria^ L. Arrow-head. Species 5. 



ORDER CXVII, 



hydrocnaeidace.c, or frogbits. 

 Genera : 



1 . LimnoUum, Richard. American Frog's-hit. ^ Sptecics : 



JLimnohium Spongia, Rich. 



2. A?iacharis, Rich. Water-weed. Species: 



Anacharis Canadeiisis, Planchon. 



3. Vallis7ieria, Micheli. Tape-grass. Eel-grass. Species : 



Vallisneria spiralis, L. 



